Accurate dispensing of compositions that flow or are otherwise poured is important in many fields of application.
Even in domestic applications, the need to protect the environment and conserve resources has led to increased interest in automatic dispensing of flowable compositions as a way to prevent incorrect or over-dispensing of active substances.
The dispensing of cleaning and scenting compositions in the toilet bowl is presently accomplished by toilet fresheners comprising single or multiple chamber containers that are hung on the rim of the toilet bowl such that active substances are rinsed out from the device with the water during the flushing of the toilet bowl.
Such toilet freshening rim hanging devices are described in WO96/38637 (Mahlhausen, et al.) and DE 101 13 036 B4 (Butter-Jentsch, et al.).
A significant disadvantage of these toilet fresheners is that dispensing substantially depends on the water flow conditions in the toilet bowl during the flushing process. These local flow conditions may differ widely as a function of toilet type and the positioning of the toilet freshener in or on the toilet bowl. For example with certain toilet types, it may happen that no active substance is released from the toilet freshener because no water, or an insufficient amount of water, flows over the toilet freshener during the flushing process. Without a flow of flush water over the toilet freshening device, the dispensing mechanism of the freshener is not initiated.
Furthermore, if flush water does flow as intended over a toilet freshening device, the flush water path intended by the toilet manufacturer is disturbed, whereby the flushing performance of a toilet may be noticeably reduced.
Active substances are usually released from such toilet fresheners by penetration of flush water through openings in the toilet freshener, partial dissolution of active substances, and a discharge of the dissolved materials out from the toilet freshener with the flush water exiting through corresponding outlets in the device. Depending on how the toilet freshener is arranged in the toilet, the strength of water flow through it may vary due to the frequent fluctuations in the flow of flush water through the outlets in the toilet bowl rim, whereby only a minimal release of active substances may be ultimately achieved.
The flush water flow stream is likely affected by the presence of a toilet freshener hanging in or on the rim of the toilet bowl. The changed flow conditions may change the flushing behavior of the toilet markedly. Frequently the flush water stream is adversely affected in such a way that water is splashed upwards out of the toilet bowl, possibly coming into contact with the user of the toilet, creating an unpleasant situation.
Moreover, many toilets are designed with a defined flush water flow path to reduce the quantity of flush water needed for complete flushing. Therefore, any interference with the flush water stream may create an inefficient flushing process that outweighs any benefit in providing freshening actives in the toilet.
There is clearly an unmet need for a toilet freshening device that can dispense active ingredients into the toilet bowl without interfering with the flow of the toilet flush water.